Trigger Analog Time Adjustment - LeCroy WaveSurfer 400 Series Service Manual

6.9.3.8 Trigger analog time adjustment

For "holdoff by time" or a trigger mode based on a SMART trigger time setting, the time accuracy is
adjusted for time settings of 100ns or less.
(In the case of a time setting longer than 100ns, the time will be accurate since it will be calculated
using a 500MHz internal reference clock.)
6.9.3.8.1 Automatic / semiautomatic adjustment
Adjustment standard
Trigger ⇒ Glitch at end of : Pos (when the output from the PSPL2600 is a positive pulse)
Setting
Adjustment method
Notes: (1) Pulse width is defined as the time width at 50% of the pulse amplitude, and therefore
(2) "Pulse 4ns" and (3)"Pulse 8ns" auto-adjustments will fail if the Glitch trigger has been
6-44 Maintenance
W≤10ns: +/-0.3ns
10ns<W≤100ns: +/-(1.5%+0.6ns)
LEVEL : Midpoint of amplitude
(1) Without inputting any signal, Open the "Maintenance1" menu and
click "64ns/32ns AnalogTime" in the "Automatic Adjustment" menu.
When the auto-adjustment is completed, save to EEPROM.
"AnalogTime Adjustment value for Interval" and "AnalogTime
Adjustment value for Pulse" are adjusted automatically. (64ns Ref4,
64nsRef3, 32nsRef4, 32nsRef4)
(2) Set the output pulse width (half-value width) of the PSPL2600 to
4.0ns±0.1ns, input this signal to CH1 and then click "Pulse 4ns" in
the "Half Adjustment" menu. When the auto-adjustment is
completed, save to EEPROM. The "4nsRef4, 4nsRef3" setting in
"AnalogTime Adjustment value for Pulse" is adjusted automatically.
(3) Set the output pulse width (half-value width) of the PSPL2600 to
8.0ns±0.1ns, input this signal to CH1 and then click "Pulse 8ns" in
the "Half Adjustment" menu. When the auto-adjustment is
completed, save to EEPROM. The "8nsRef4, 8nsRef3" setting in
"AnalogTime Adjustment value for Pulse" is adjusted automatically.
(4) Set the output frequency of the SG-503 to 250MHz (4.0ns±0.1ns
cycle), input this signal to CH1 and then click "Interval 4ns" in the
"Half Adjustment" menu. When the auto-adjustment is completed,
save to EEPROM. The "4nsRef4, 4nsRef3" setting in "AnalogTime
Adjustment value for Interval" is adjusted automatically.
(5) Set the output frequency of the SG-503 to 125MHz (8.0ns±0.1ns
cycle), input this signal to CH1 and then click "Interval 8ns" in the
"Half Adjustment" menu. When the auto-adjustment is completed,
save to EEPROM. The "8nsRef4, 8nsRef3" setting in "AnalogTime
Adjustment value for Interval" is adjusted automatically.
unless the trigger level has been set to 50% of the pulse amplitude, adjustments will be
unsuccessful.
set with the wrong polarity.